One kind of known switching arrangement or apparatus is described in commonly assigned U.S. Pat. No. 4,500,991, granted Feb. 18, 1985 and entitled "Circuit Arrangement For the Control of the Transmission of Digital Signals, Particularly PCM Signals, Between Stations of A Time Division Multiplex Telecommunication Network...", which patent is hereby incorporated by reference, and which corresponds to German Pat. No. 2,915,488. In such an arrangement, it has been found that occasionally the facilities of connection for the several connection circuits, which may be subscriber circuits and office relays, are too sharply limited. Also, the communication capacity of this switching arrangement has sometimes been considered inadequate, which has provided a motive for enlarging the switching arrangement.
To enhance the communication capacity of a switching arrangement of the kind initially referred to, it might first occur to one to replace the loop arrangement interconnecting the several loop buses by a coupling network. Coupling networks for time multiplex communications systems are known in considerable numbers (NTTZ 1970, No. 9, pages 465 to 471). The known coupling networks comprise space and time stages in various combinations. A disadvantage of using such coupling networks to enhance the initially considered switching arrangement, however, is that the existing circuit structure presupposed by the switching arrangement would have to be completely altered.
There is also known a digital communications system with divided control (Der Fernmelde-Ingenieur, No. 6, June 1984) in which use is made of a coupling network consisting of individual coupling blocks. To expand this communications system, corresponding coupling stages are provided. A disadvantage here is that depending on load condition of the communications system, differing transit times may occur within the communications system for a given route.
A main object of the present invention is to further develop the initially specified switching arrangement such that connection facilities for the several connection circuits are expanded, and such that the communications capacity of the switching arrangement is expandable in accordance with the needs or desires of the situation presented by a given case.